.wrap{
    width: 100%;
    height: 100%;
    position: fixed;
    top: 0;
    left: 0;
    z-index: 100;
    img{
        width: 4rem;
        height: 4rem;
        top: 50%;
        left: 50%;
        position: absolute;
        transform: translate(-50%,-50%);
    }
}